Propulsion devices

ABSTRACT

THE INTAKE DUCT OF A PROPULSION DEVICE FOR A WATER-BORNE VESSEL IS DEFINED BY FIRST AND SECOND MEMBERS, ONE OF WHICH PROVIDES THE MAJOR PORTION OF THE WALL OF THE INTAKE DUCT AND THE OTHER OF WHICH EXTENDS BETWEEN AN INLET OPENING AND AN OUTLET OF THE INTAKE DUCT.

United States Patent 1 1 Usborne 45 v 21 1974 PROPULSION DEVICES [56] References Cited [75] Inventor: Andrew Charles Usborne, Sheffield, UNITED STATES PATENTS England 915.255 3/1909 Weisz 60/222 3,475,912 ll/l969 A 60/222 [73] Ass1gnee: UA Engine ring Llmlteisheffieldq 3,336,752 8/1967 60/221 V 7 2,993,463 7/1961 McKinney... 60/222 X [22] Fil Nov- 1971 3,342,032 9/1967 Cox 60/221 [21] Appl. No.: 198,562 Primary ExaminerC1arence R. Gordon W Attorney, Agent, or Firm-Irvin S. Thompson et a1. [30] Foreign Application Priority Data Noy. 13 ,197() r r at13 1mm 2 1 70 [57] ABSTRACT The intake duct of a propulsion device for a water- [52] US. Cl. 115/14, 60/221 borne vessel is defined by first and second members, [51] Int. Cl B63h 11/02 one of which provides the major portion of the wall of [58] Field of Search 60/221, 222; '1 15/14, 34 A, the intake duct and the other of which extends between an inlet opening and, an outlet of the intake duct.

4 Claims, 3 Drawing Figures PATENTED MAY 2 1 m4 SHEET 1 [IF 2 FATENTEUHAYZI' m4 3.811.397

SHEET 2 OF 2 Fla. 3.

PROPULSION DEVICES BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to propulsion devices for water-borne vessels.

2. Description of the Prior Art Jet propulsion devices are known which comprise an intake duct, and outlet duct and a rotary impeller mounted between the intake and outlet ducts and in which the intake duct has an inlet opening and an outlet which communicates with the outlet duct via the rotary impeller, the intake duct being so shaped that, in use, flow of fluid through the inlet opening is in a different direction to flow of fluid through the outlet thereof.

It is an object of the invention to provide an improved jet propulsion device of the above kind in which the means forming the intake duct-are such as to improve and simplify manufacture of the device.

SUMMARY OF THE INVENTION The intake duct is defined by first and second members, the first member defining the major portion of the wall of the intake duct and the second member being attached to the first member and defining the remainder of the wall of the intake duct.

BRIEF DESCRIPTION OF THE DRAWINGS DESCRIPTION OF THE PREFERRED EMBODIMENTS The vessel hull shown in the drawings is moulded from glass-fibre-reinforced polyester resin with a rear section formed to provide an intake duct 11 which sweeps upwardly and rearwardly from a bottom intake opening 12 to a rear transom 13 at the bottom of which the duct outlet 14 is formed. Within the formed section and above the intake opening 12 there is a mounting 15 for a shaft bearing and seal assembly 16 disposed in line with the centre of the circular-outlet 14.

The assembly 16 includes a main body 17 having an end face 18 in which a plurality of tapped apertures (not shown) are formed for the reception of threaded fasteners for attachment of the body 17 to a wall 19 of the formed section. The body 17 is formed integrally with a flange 20 the configuration of which is such that it forms a continuation of the adjacent parts 21 and 22 of the wall of the intake duct 11. The body 17 contains a pair of sealing arrangements 23 and 24 disposed one on each side of a roller bearing 25 for supporting the shaft 26. The shaft 26 has a threaded end portion 27 for attachment thereof to a drive element of an engine 'within the hull and a spacer 28 of hexagonal external A propulsion unit attached to the formed section comprises a rotary axial flow impeller 29 within a casing 30 which has a flange 31 which is bolted to the back of the transom 13. The impeller casing is formed integrally with an outlet duct 32 from the rear end of which the propulsion jet issues. The impeller drive shaft 26 extends rearwardly through the intake duct 11 to the casing 30 within which it is supported by a bearing 33 contained within a bearing housing 34 connected by vanes 35 to the outlet duct 32.

The formed hull section provides the side walls and the top wallof the intake duct 11 the bottom wall of which is provided by a separately fitted member 36 which extends from the rear of the intake opening 12 to the transom 13 thus blanking off part of a bottom opening initially formed in the hull moulding. A plurality of rods, of which one 37 is shown in the drawings, extend forwardly of the member 36 across the intake opening 12 to exclude flotsam and other debris from the intake duct 11. Each rod 37 has its rear end received in a socket in the member 36 and its forward end received in a socket in the formed section of the hull.

As shown in FIG. 3, the.cross-sectional configuration of the intake duct 11 varies from the inlet end to the outlet end, the sections A-A, BB,.C-C, DD and EE of FIG. 1 corresponding to the lines A, B, C, D or E respectively of FIG. 3. The spacings between the sections A-A, B-B, C-C, DD and E-E are the same. The approximate centre line of the intake duct 1 1 is indicated by the line V-W of FIG. 1 and the front and rear extremities of the inlet opening 12 are indicated at X and Y respectively. It is to be noted that the section line C-C has been taken through the flange 20 which forms part of the wall of the intake duct and that the end wall 19 of the mounting 15 engaged by end face 18 of the body 17 is of generally rectangular form.

The fore and aft dimension of the inlet opening 12 as measured in the direction X-Y is greater than the diameter of the intake duct 11 as measured in a plane at right angles to the line V-W which in turn is approximately twice the diameter of the discharge duct 32 as measured immediately to the rear of the bearing housing 34.

The line V-W extends initially at an inclination to the horizontal of 35-and the longitudinal profile of the formed section of the hull is such that the midpoint of the duct is defined by a line which initially is of arcuate form and merges into a straight line inthe'vicinity of the flange 20 and then becomes arcuate terminating at its rearward end in a portion inclined downwardly relative to the horizontal.

The separately fitted member 36 has a flat bottom 41 which provides a pair of side flanges 42 for bolting of the member 36 to the formed sectiomSide walls 43 extend upwardly from the flat bottom 41 and the upper edge 44 of each side wall 43 is inclined rearwardly at an angle of 35 parallel to the line V--W. The upwardly presented surface of the member 36 is of arcuate form in transverse section varying in a smoothly curved manner from an almost flat configuration at the forward end thereof to a semi-circular form at the rear thereof.

As shown the separately fitted member 36 is formed in one piece but it is to be understood that it may be formed as two or more pieces,.for example, there may be a front piece which is formed with sockets to receive the ends of the rods 37 with said front piece attached 3 to a main bodywhich provides the major part of the separately fitted member.

The outlet duct 32 carries a steering unit comprising a pair of buckets 38 and the lower portion of the wall of the outlet duct is cut away at 39 to provide a lower discharge opening. A vane 40 is positioned adjacent the lower discharge opening to deflect water issuing therethrough in a forward direction.

As described in British Patent Specification No. 1,190,735 the two buckets 38 are pivotable about a common vertical axis and are controllable to deflect the water jet issuingthrough the outlet duct for steering purposes.

The buckets are also movable into positions in which they close the outlet duct 32 to deflect the jet downwardly through the lower discharge opening and thus forwardly, beneath the hull.

As shown the transom 13 is inclined rear-wardly and upwardly so that the jet, which, in forward movement, issues at right angles to the transom, has a slight downward component.

1 claim:

1. A waterborne vessel having a hull having a formed section and a transom, the vessel having propulsion means comprising an intake duct extending between an inlet opening formed in the base of the vessel and an I outlet opening in line with the transom, an outlet duct arranged in communication with the intake duct, an impeller mounted between the two ducts and means for the transmission of drive to said impeller, said intake duct being defined in part by said formed section of the hull of the vessel, said section providing a downwardly open channel extending longitudinally of the vessel from said inlet opening to the transom and that part of said channel which is adjacent the transom being closed by a separately fitted member which defines the rear edge of the inlet opening and a portion of the wall of the intake duct, said intake duct being so shaped that water entering the intake duct has an upward component of velocity whereas water discharged through the outlet opening has a downward component of velocity.

2. A vessel according to claim 1 wherein said separately fitted member has a substantially straight transversely extending leading edge defining said rear edge of the inlet opening and a pair of side walls the upper edges of which are rearwardly and upwardly inclined, the base of said member having side flanges for the reception of bolts for attachment of the separately fitted member to the formed section of the hull.

3. A vessel according to claim 1, wherein said separately fitted member has a rear end portion the upper surface of which is of substantially semi-circular form in transverse cross-section, said rear end portion defining the lower part-of the outlet of theintake duct.

4. A vessel according to claim 1, wherein the means for transmission of drive to the impeller comprises a drive shaft which is inclined to the horizontal and which is supported by bearing means disposed in a recess in the wall of the formed section of the hull. 1F l 

